The invention relates to a flat key for a tumbler-containing locking cylinder of a locking apparatus, with a key grip and, attached thereto, a key shank for locking grooves cut into the shank towards the end surface, the key shank having a basic profile exhibiting an essentially T-shaped cross-sectional configuration, of which the T-bar forms a guide bar with guiding surfaces, and of which the T-stem extending in the longitudinal mid-plane provides the end surface and has wide side surfaces for the provision of profile ribs that have curvilinear cross-sectional contours.
A flat key of the kind under discussion is known from DE1928504A1, in which the T-shaped basic profile forms a rectangularly arranged T-stem with a T-bar extending perpendicularly thereto. In order to accommodate different variations in the lock assembly profile, profile ribs are provided on the wide side surfaces in varying sequence, the profile ribs having curvilinear cross-sectional contours. Although such profile ribs are present, they are often accompanied by sharp edges or angles, which can lead to scratching and also to injury.